Inks for in-mould decoration

ABSTRACT

An energy-core ink or varnish composition is provided for use in an in-mold decoration (IMD) process, comprising an energy-curable resin, additional reactive monomers and/or oligomers and, optionally and in an amount not exceeding 10% by weight, a solvent, wherein the resin comprises a urethane acrylate oligomer having an aromatic or aliphatic polycarbonate backbone. For inks, the composition additionally includes a pigment or dye. For photocure compositions, a photoinitiator is also included. Also provided is an in-mold decoration (IMD) process employing the ink or varnish composition.

The present invention relates to a new ink composition for in-moulddecorative use and to an in-mould decorative process employing this ink.

In its broadest sense, in-mould decorating (IMD) simply means applying adecoration in the course of moulding the decorated part. A particularIMD process referred to as insert moulding or insert IMD has been knownfor many years, but has seen little practical uses except in theautomotive industry, until recently. In insert IMD processes, a filmsubstrate is printed with the desired decoration this is preferably asecond surface printing process in which the decoration is printed inreverse on the reverse side of a transparent or translucent (orpartially transparent or translucent) film substrate, so that it showsthrough and is protected by the substrate. Then, in one or more steps,the substrate is, if necessary, formed into shape and further resin orplastics material is injection moulded to give the final product.

It will be seen readily that this process can give rise to severaldifficulties. First, if the printed substrate is to be moulded afterprinting, the printing ink must have the necessary mechanical propertiesto wild the strains of moulding. Thus, it must be flexible, andpreferably have at least a similar flexibility to that of the substrate,so as to stretch with the substrate as the substrate is moulded. It mustalso have sufficient adhesion to the substrate and abrasion resistanceto withstand any abrading action in the course of moulding.

In the final step, where a liquid resin or resin precursor is injectedonto the formed decorated substrate, the printing ink must be able toresist the heat, pressure and shear imparted to it by the resininjection, or it has to be protected with an additional layer.Otherwise, the ink will be caused to degrade or smudge from its printedlocation by the injection process, resulting in so-called “wash-out”.

Finally, the ink has to be compatible with the injected resin and inparticular must provide a good adhesion with the injected resin so as toprevent delamination of the printed substrate from the resin backfill.

One way of solving the problems of avoiding wash-out of the ink andensuring good adhesive bond strength to the resin backfill has been toprovide the printed substrate with an additional coating over the irkwhich additional coating is typically an aqueous laminating adhesivethat is applied over the graphic inks. This coating then serves to bondor laminate an additional sheet of substrate such that the ink issandwiched between the substrate and the additional sheet of substrate.In this twin-layer construction, the laminated substrate serves toprotect the ink against wash-out by the backfill injection and providesgood adhesion to the injected resin. However, this construction methodrequires additional processing steps and material cost.

DE-A-19832570 discloses a solvent-based ink system comprising a blend ofa polycarbonate and a thermoplastic polyester polyurethane. U.S. Pat.No. 5,648,414 discloses a solvent-based ink suitable for insert IMD,containing a polycarbonate based on geminally disubstituted,dihydroxydiphenyl cycloalkanes as binder. One such ink is commerciallyavailable as Noriphan™ (ex Proll under licence from Bayer AG). Whilstthis solvent-based ink permits a single-layer printed substrateconstruction to be used in IMD processes, it is associated with certaindisadvantages. For example, because it is a solvent-based ink, it isrelatively difficult or inconvenient to screen print due to its poorpress stability and difficulties in washing up. Also, the printedsubstrate has been found to be susceptible to curling, and it is oftentherefore difficult to place the printed substrate in registration inthe mould tool prior to injection with the resin backfill. Furthermore,it is essential to ensure that all solvent is completely removed beforethe printed substrate is formed and injection moulded, in order toprevent wash-out, and blister or bubble formation, leading todelamination. Another disadvantage is that the range of coloursavailable is limited due to the fact that certain pigments can breakdown the polymer resin. Finally, the need for a solvent in the ink hasobvious environmental and health hazard implications.

These deficiencies associated with solvent-based systems have led to thedevelopment of photocurable ink systems, for example inks curable byUV-energy, for use in IMD processes, which require less or no solvent.However, existing UV-curable inks are not wholly satisfactory,particularly in terms of formability, washout resistance and adhesion toinjected resin backfill. It will be appreciated that inks suitable forIMD must have very good adhesion to the substrate, good flexibility andelongation to permit forming with the substrate, good mechanicalresistance to abrasion by the moulds, good washout resistance to theresin injection step, and good adhesive bonding to the injected resinbackfill. Because UV-curable inks undergo cross-linking, it is far moredifficult to achieve this combination of properties in a UV-curable inkthan in a solvent-based ink.

Although these UV-curable ink systems have eliminated or reduced thesolvent, and hence the problems associated with the use of solvent in asolvent-based ink system the need for flexibility and elongation hasmeant that the inks have tended to be too so* to withstand themechanical impact of the forming and injection processes. In additionadhesion to the resin backfill was often not satisfactory. Therefore, itwas generally still found necessary to provide the printed substratewith a protective or tie coating, in order to ensure adequate resistanceto the resin injection process and to provide good bonding to thebackfill resin, so as to avoid wash-out, delamination, or both. Inaddition to boost adhesion to the substrate and avoid delamination atthe ink:substrate interface, it was generally still necessary to includeaggressive monomers, such as N-vinyl-2-pyrrolidone (NVP), in the ink,which in turn have associated drawbacks, for example they may lead todelamination due to unreacted material, and to health and safetyconcerns.

We have now found, surprisingly, that it is possible to provide anenergy-curable composition, preferably a UV-curable ink, suitable foruse in IMD processes, that can be printed onto a substrate, that allowsthe printed substrate to be formed using conventional formingtechniques, and backfilled with a resin injection without undergoingwash-out, even in the absence of a protective coating. Furthermore, theink can provide excellent adhesion to the resin backfill without theneed for a tie coating. Because the claimed energy-curable resincomposition gives improved adhesion the requirement for NVP is reducedor eliminated. A fisher advantage is that solvent may be significantlyreduced or even eliminated from the IMD process. The reduction orremoval of solvent or NVP, or both, may lead to further advantages,apart from obvious environmental and health considerations, such asreduced delamination of the final part especially in environmentaltesting, caused by poor removal or poor full reaction of potentiallyvolatile materials.

In addition, we have found that ink compositions according to thepresent invention can provide a harder, tougher surface, when cured,than conventional insert IMD inks that contain high molecular weighturge acrylate resins, whilst exhibiting excellent flexibility andforming characteristics. It will be appreciated that hardness andtoughness are desirable in an insert IMD ink in order to avoidaccidental marking or damage caused by forming or moulding tools.

Broadly speaking, this has been achieved by using a new urethaneacrylate resin having a polycarbonate backbone as carrier for thepigment or dye.

Accordingly, in a first aspect, the present invention provides anenergy-cure ink or varnish composition for use in an in-mould decoration(IMD) process, comprising an energy-curable resin, additional reactivemonomers and/or oligomers and, optionally and in an amount not exceeding10% by weight of the composition, a solvent, wherein the energy-curableresin comprises a urethane acrylate, oligomer having an aromatic oraliphatic-polycarbonate backbone.

In a second aspect, the invention provides a method of in-moulddecoration employing the ink or varnish composition.

By “energy-curable resin” or “energy-cure compositions”, as used herein,is meant a resin or composition that is curable by exposure to a sourceof radiation of an appropriate wavelength or intensity, i.e. isphotocurable by exposure to a source of electromagnetic radiation of anappropriate wavelength, such as ultraviolet (UV) radiation, or iselectron beam (EB) curable by exposure to an electron beam of anappropriate intensity. Preferably, the energy-cure compositionsaccording to the present invention are at least UV-curable.

The energy-cure compositions according to the invention contain anenergy-curable resin, additional reactive monomers and/or oligomers,additives and, in the case of an ink composition, pigments or dyes. Inthe case of photocure compositions such as UV-cure compositions, aphotoinitiator is also included in the composition.

Energy-Curable Resin:

The energy-curable resin at least comprises a mono-, di- ortrifunctional urethane acrylate oligomer that has a polycarbonatebackbone and is obtainable by reaction of a diisocyanate, a hydroxy(meth)acrylate functional unsaturated monomer and a polycarbonatepolyol. Preferably, the resin at least comprises a mono- or difunctionalurethane acrylate oligomer, as represented by the general formula (I) or(II):

wherein:

R₂ and R₃ are such that OCN—R—NCO (where R=R₂ or R₃) represents thediisocyanate used in the synthesis;

Y represents a hydrogen atom or a methyl group;

R₁ and R₄ together with their attached (meth)acrylate group representthe residue of the hydroxy (meth)acrylate functional unsaturated monomerused in the synthesis.

Examples of the diisocyanate compounds include, but are not limited to,hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI),4,4-dicyclohexylmethane diisocyanate (H₁₂MDI), 2,2,4-trimethylhexamethylene diisocyanate 2,4-tolylene diisocyanate (TDI), 2,6-tolylenediisocyanate (TDI), trimethylhexamethylene diisocyanate (TMDI),diphenylmethane diisocyanate (MDI), tetramethylxylene diisocyanate(TMXDI), and xylene diisocyanate (XDI). A preferred isocyanate isisophorone diisocyanate (IPDI) because of improved resistance andselective reactivities of the isocyanate groups enabling preparation ofan ethylenically unsaturated monoisocyanate. The above diisocyanatecompounds may be used individually or in combination.

Examples of the hydroxy (meth)acrylate functional unsaturated monomersinclude, but are not limited to, 2-hydroxyethyl acrylate, 2-hydroxyethylmethacrylate, 2-hydroxypropyl acrylate, 1,4-butanediol monoacrylate andglyceryl diacrylate, trimethylolethane di(meth)acrylate.

Suitable polycarbonate polyols are represented by the general formula(III):

wherein:

R⁵ and R⁶ represent the same or different aliphatic or aromatic groups;and

n is an integer of 1 to 60.

The polycarbonate polyols can be produced through, for example, an esterinterchange reaction or alcoholysis of diethyl carbonate or diphenylcarbonate with a polyol, preferably a diol such as an alkylene diol,e.g. 1,4-butane diol, 1,6-hexane diol, or an alkylene ether diol. e.g.triethylene glycol, tripropylene glycol. Other suitable diols include2,2-bis-[4-(2-hydroxypropoxy)phenyl]propane and1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethyl cyclohexane.

Polyols with three or more hydroxyl groups, such as trimethylol propane,glycerine and pentaerythritol, can be incorporated for preparingpolycarbonate polyols suitable for synthesising trifunctionalpolycarbonate urethane acrylates.

Mixtures of the polycarbonate polyols may also be utilised in thesynthesis. Other polyols such as polyether- or polyester-polyols mayalso be included, although to achieve the desired IMD properties thebackbone should be substantially polycarbonate in nature.

The polycarbonate backbone may be aliphatic or aromatic but preferablyis aliphatic in nature. It may be linear or branched, and is preferablylinear.

Suitable polycarbonate backboned urethane acrylates are available as NTX4711 and NTX 4867 (ex Sartomer). RD2/105. RD2/106. RD3/101, RD3/102,RD4/103 and RD4/104 (ex UCB Chemicals SA), and RXX-01-344 (ex Rahn).

We prefer that the polycarbonate urethane acrylate (PCUA) oligomer has aaverage molecular weight in the range of from 1,000 to 30,000, morepreferably from 3,000 to 15,000, still more preferably from 4,000 to10,000, and in particular from 6,500 to 10,000. For the purposes ofproviding improved flexibility and elongation, higher molecular weightpolycarbonate backbones would be desirable. However, higher molecularweights can have an adverse effect on the viscosity and printability ofthe ink. Moreover, higher molecular weights tend to produce unduly softink coatings, which are more susceptible to marking by mould parts orduring handling. Thus, it will be appreciated that the particularmolecular weight chosen will represent a compromise between theseconflicting factors, on the one hand providing acceptable flexibilityand elongation whilst on the other hand, ensuring satisfactoryviscosity, printability and hardness.

If desired, the flexibility, elongation and hardness properties of theink can be tailored by blends of monofunctional, difunctional ortrifunctional PCUA oligomer. It will be appreciated that the higherdegrees of cross-linking afforded by inclusion of di- and trifunctionaloligomers will tend to reduce the overall flexibility and elongation ofthe ink, and increase its hardness.

Thus, the energy-curable resin may comprise a mono-, di- ortrifunctional polycarbonate urethane acrylate oligomer, or a blend oftwo or more of mono-, di- and trifunctional polycarbonate urethaneacrylate oligomers. Preferably, the energy-curable resin at leastcomprises a mono- or difunctional polycarbonate urethane acrylateoligomer, or a blend thereof. We prefer that the average functionalityof the energy-curable resin is less than 2.5, more preferably less than2.2, and most preferably less than 2.1.

The monofunctional polycarbonate urethane acrylate may be present in thecomposition in an amount of from 0 to 70% by weight. Difunctionalpolycarbonate urethane acrylate may be included in an amount from 0 to50% by weight. Trifunctional polycarbonate urethane acrylate may beincluded in an amount from 0 to 5% by weight. The total polycarbonateurethane acrylate component is present in an amount of from 5 to 70%,preferably from 20 to 60%, by weight of the composition.

Photoinitiators:

Preferably the compositions according to the invention are at leastphotocurable, and most preferably are UV-curable, and accordinglycontain a photoinitiator. However, it will be appreciated that EB-curecompositions in accordance with the invention can be formulated withoutthe need for a photoinitiator.

For photocure compositions such as UV-cure compositions, a wide range ofcommercially available photoinitiators can be incorporated to initiatethe photocure mechanism. Preferably these photoinitiators have lowpotential to migration and low volatility, so as to avoid problems suchas delamination of the injection moulded part. The photoinitiatorpackage should also have low UV thermal yellowing, important to meettypical heat and environmental cycling tests typically used on the finalIMD part. The photoinitiator package is typically present in an amountof from 0.5 to 20% for example from 1 to 14%, by weight of thecomposition.

Suitable photoinitiators include, for example, 2,4,6-trimethylbenzyldiphenyl phosphine oxide (Lucerin™ TPO, ex BASF),bis(2,4,6-trimethylbenzoyl)phenyl phosphine oxide (Irgacure 819, ex CibaGeigy), bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentyl phosphine oxide,ethyl-2,4,6-trimethylbenzoylphenyl-phosphinate (Lucerin™. TPO-L, exBASF), 2-benzyl-2-dimethylamino-1-(4-morpholinphenyl) butan-1-one(Irgacure™ 369, ex Ciba Geigy), 1-hydroxycyclohexyl acetophenone(Irgacure™ 184, ex Ciba Geigy), iso-propyl thioxanthone (Quantacure™ITX, ex IBIS or Speedcure™ ITX, ex Lambson; 2-chloro thioxanthone(Kayacure™ CTX, ex Nippon Kayaku),oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone and2-hydroxy-2-methyl-1-phenyl-1-propanone (Esacure™ KIP100F, ex Lamberti),methyl benzoyl formate (Genocure MBF ex Rahn), benzophenone,2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one (Irgacure™907, ex Ciba Geigy). Of these, 2,4,6-trimethylbenzoyl diphenyl phosphineoxide (Lucerin™ TPO, ex BASF), bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (Irgacure 819, ex Ciba Geigy), andbis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentyl phosphine oxide arepreferred photoinitiators.

Additional Reactive Monomers and/or Oligomers:

Additional reactive energy-cure monomers and/or oligomers may be presentin an amount of from 0 to 80%, preferably from 0 to 60%, by weight ofthe composition. These reactive monomers and/or oligomers are preferablymonofunctional.

Suitable acrylate monomers or oligomers include, but are not limited to,isobornyl acrylate (IBOA), 2-phenoxy ethyl acrylate (2PEA),2-(2-ethoxyethoxy) ethyl acrylate (EOEOEA). CTF acrylate,4-t-butylcyclohexyl acrylate. THF-acrylate, alkoxylated acrylates,diethylene glycol diacrylate, dipropylene glycol diacrylate,1,6-hexanediol diacrylate, low molecular weight monofunctional urethaneacrylates, polyether acrylates, polyester acrylates and low molecularweight epoxy acrylates.

Non-acrylated reactive diluents that may be incorporated include, butare not limited to, acryloyl morpholine (ACMO), n-vinylformamide (NVF),n-vinylformamide derivatives and n-vinyl caprolactam (NVC).

The compositions of the invention can provide improved adhesion to thesubstrate and backfill, thereby advantageously allowing theincorporation of N-vinyl-2-pyrrolidone (NVP) to be significantly reducedor even eliminates NVP is conventionally used to boost adhesion to thesubstrate, but concerns about health and safety, and its effect due tothe volatility of unreacted material on delamination, means that itwould be advantageous to eliminate, or at least reduce, NVP.Nevertheless, in certain cases it will still be desirable to includemonomers such as NVP in the ink and varnish compositions of theinvention, to improve ‘key’ to substrate. If used, NVP can beincorporated in an amount not exceeding 30%, preferably not exceeding15%, more preferably not exceeding 10%, and in particular not exceeding5%, by weight of the composition. Most preferably, the composition isfree of NVP.

Additives:

If desired, inert or passive resins such as acrylics, styrene acrylates,polyesters, polycarbonates or celluloses may be included in the ink insmall amounts, in order to improve the adhesion of the ink coating.However, these inert or passive resins tend to adversely affect theresistance of the ink to injection of the backfill resin, and thusincrease the likelihood of wash-out. If included, therefore, we thatonly a small amount is used, for example an amount not exceeding 10%,and preferably not exceeding 7%, by weight of the composition.

Additives such as wetting agents, silicone and non-silicone antifoamsmay be incorporated to improved print properties such as substratewetting and flow-out, and may be included in an amount of from 0 to 5%,preferably from 0 to 2%, by weight of the composition. It should benoted that some additives, typically with low molecular weights, mayhave a tendency to migrate to the print surface in the cured coating.This can affect the IMD properties, and therefore the total additivecontent should be kept to a minimum and additives with a high migrationpotential avoided.

Where the composition is intended for use as an ink, instead of avarnish, a pigment or dye is included in the composition. Organic and/orinorganic pigments or dyes can be incorporated in an amount of from 0 to50%, preferably from 0 to 40%, by weight of the composition. Thepigments or dyes should be selected to have good resistance to thermaldecomposition and change, and resistance to sublimation.

Suitable pigments include, but not limited to, titanium dioxide white,zinc sulphide, carbon black, azo diarylide yellow, isoindoline yellow,diarylide orange, quinacridone magneta, diketo-pyrrolo-pyrrol red,copper phthalocyanine blue, copper phthalocyanine green, dioxazineviolet, diketometal oxides. Speciality effect pigments, such as metaloxide-coated mica pigments and aluminium metallic pigments, can also beincluded.

Fillers may be included to control the viscosity and rheology of thecomposition typically to improve printing characteristics, and may bepresent in an amount of from 0 to 40%, preferably from 0 to 30%, byweight of the composition.

Suitable fillers include, but not limited to, calcium carbonate, chinaclay, aluminium hydrate, talc, barium sulphate, aluminium silicate, andsilica.

It will be appreciated that the compositions according to the inventionwill be substantially free of organic solvent. However, small amounts oforganic solvent may be included, if needed, in amounts not exceeding10%, and preferably not exceeding 5%, by weight of the composition. Mostpreferred is that the composition is free of organic solvent.

In-Mould Decorating (IMD) Process:

The energy-cure compositions of the invention are particularly suitablefor use in IMD processes, and especially in insert IMD or insertmoulding processes. The application of the compositions to the substratemay be effected using conventional printing techniques. Preferredtechniques include flexographic, lithographic, digital and screen printprocesses, but other methods may be used as appropriate. Application byscreen printing is particularly preferred.

Suitable substrate materials onto which the ink may be printed or thevarnish applied as the case may be, include print-receptive polyester,polycarbonate, ABS. PMMA, polycarbonate/polyester blends,polycarbonate/ABS blends materials such as those supplied by Bayer AG(Bayfol®, Makrolon®, Marofol®, Bayblend®), GE Structured Products(Lexan®) and Autotype (Autoflex Hiform™, Autoflex XtraForm™).Preferably, the substrate is of a polycarbonate orpolycarbonate/polyester blend resin material.

Similarly, suitable backfill materials which may be injected onto theprinted substrate include the following or blends of the following:polyesters polycarbonate, styrenes ABS and PMMA resin materials.Preferably, the injected backfill is of polycarbonate or apolycarbonate/polyester blend resin material.

The invention will be further illustrated by reference to the followingnon-limiting Examples:

EXAMPLES

A) Formulations:

EXAMPLE 1 Comparative

Solvent-Based IMD Technology

A sample of Noriphan™ black HTR952 was obtained (ex Proll) forcomparison to UV IMD ink technology.

Prints of Noriphan™ were prepared in accordance to the Noriphan™ productdata sheet supplied by Proll. The prints were examined for adhesion,surface hardness, print curl, forming, and IMD properties.

Example 2 Comparative

Standard Flexible Urethane Acrylate Technology

The following screen ink composition was prepared by first premixing thematerials and then grinding the resultant mixture on a triple roll milluntil a grind of <12 microns (μm) was achieved.

Urethane acrylate, Actilane ™ 290 24.0 IBOA, SR506 ex Sartomer 31.8 NVPex BASF or ISP 12.0 Silicone antifoam 0.7 UV Stabiliser, Genorad ™ 16 exRahn 0.5 Lucerin ™ TPO ex BASF 4.0 Irgacure ™ 184 ex Ciba 3.0 Filler20.0 Carbon Black 4.0 Total (weight %) 100.0

Single and multilayer prints of the above screen ink composition wereprinted through a 150-34 mesh onto a polycarbonate substrate and curedusing a medium pressure mercury lamp (80 Wcm⁻¹). The prints wereexamined for adhesion, surface hardness, forming, and IMD properties.

Example 3 Invention

Polycarbonate Urethane Acrylate Technology

The following screen ink composition was prepared by first premixing thematerials and then grinding the resultant mixture on a triple roll milluntil a grind of <12 microns (μm) was achieved.

PCUA, NTX 4867 34.3 IBOA, SR506 ex Sartomer 23.5 UV Stabiliser,Genorad ™ 16 ex Rahn 0.5 Silicone antifoam 0.7 Lucerin ™ TPO ex BASF 4.0Quantacure ™ ITX ex IBlS 1.0 NVP ex BASF 12.0 Filler 20.0 Carbon Black4.0 Total (weight %) 100.0

Single and multilayer prints of the above screen ink composition wereprinted through a 150-34 mesh onto a polycarbonate substrate and curedusing a medium pressure mercury lamp (80 Wcm⁻¹). The prints wereexamined for adhesion, surface hardness, print curl, forming, and IMDproperties.

Example 4 Invention

Polycarbonate Urethane Acrylate Technology (NVP Free)

The following screen ink composition was prepared by first premixing thematerials and then grinding the resultant mixture on a triple roll milluntil a grind of <12 microns (μm) was achieved.

PCUA, NTX 4867 ex Sartomer 36.4 EOEOEA, S256 ex Sartomer 8.7 IBOA, SR506ex Sartomer 11.9 NVC, ex BASF or ISP 18.1 Polyester urethane acrylate exRahn 3.8 UV stabiliser, Genorad ™ 16 ex Rahn 0.4 Lucerin ™ TPO ex BASF4.7 Irgacure ™ 184 ex Ciba 2.6 Silicone antifoam 0.7 Carbon black 3.6Filler 9.1 Total (weight %) 100.0

Single and multilayer prints of the above screen ink composition wereprinted through a 150-34 mesh onto a polycarbonate substrate and curedusing a medium pressure mercury lamp (80 Wcm⁻¹). The prints wereexamined for adhesion, surface hardness, forming, and IMD properties.

Example 5 Invention

Polycarbonate Urethane Acrylate Technology (NVP Free)

The following screen ink composition was prepared by first premixing thematerials and then grinding the resultant mixture on a triple roll milluntil a grind of <12 microns (μm) was achieved.

PCUA, NTX 4867 40.0 IBOA, SR506 ex Sartomer 11.8 UV Stabiliser,Genorad ™ 16 ex Rahn 0.5 Silicone antifoam 0.7 Lucerin ™ TPO ex BASF 4.0Irgacure ™ 184 ex Ciba Geigy 1.0 ACMO ex Rahn 18.0 EOEOEA, SR256 exSartomer 8.0 Filler 10.0 Red 6.0 Total (weight %) 100.0

Single and multilayer prints of the above screen ink composition wereprinted through a 150-34 mesh onto a polycarbonate substrate and curedusing a medium pressure mercury lamp (80 Wcm⁻¹). The prints wereexamined for adhesion, surface hardness, forming and IMD properties.

Example 6 Invention

Polycarbonate Urethane Acrylate Technology (NVP Free)

The following screen ink composition was prepared by first premixing thematerials and then grinding the resultant mixture on a triple roll milluntil a grind of <12 microns (μm) was achieved.

PCUA, RD2/105 ex UCB 25.8 EOEOEA, S256 ex Sartomer 6.0 IBOA, SR506 exSartomer 37.2 ACMO ex Rahn 7.0 UV stabiliser, Genorad ™ 16 ex Rahn 0.3Lucerin ™ TPO ex BASF 4.0 Genocure ™ MBF ex Rahn 2.0 Speedcure ™ ITX exLambson 1.0 Silicone antifoam 0.7 Phthalocyanine blue 6.0 Filler 10.0Total (weight %) 100.0

Single and multilayer prints of the above screen ink composition wereprinted through a 150-34 mesh onto a polycarbonate substrate and curedusing a medium pressure mercury lamp (80 Wcm⁻¹). The prints wereexamined for adhesion, surface hardness, forming, and IMD properties.

Example 7 Invention

Polycarbonate Urethane Acrylate Technology

The following screen ink composition was prepared by first premixing thematerials and then grinding the resultant mixture on a triple roll milluntil a grind of <12 microns (μm) was achieved.

PCUA, RXX0] 344 ex Rahn 26.0 IBOA, SR506 ex Sartomer 27.0 NVP ex BASF orISP 12.0 UV stabiliser, Genorad ™ 16 ex Rahn 0.3 Lucerin ™ TPO ex BASF4.0 Silicone antifoam 0.7 Titanium dioxide white pigment 30.0 Total(weight %) 100.0

Single and multilayer prints of the above screen ink composition wereprinted through a 150-34 mesh onto a polycarbonate substrate and curedusing a medium pressure mercury lamp (80 Wcm⁻¹). The prints wereexamined for adhesion, surface hardness, forming, and IMD properties.

Example 8 Invention

Polycarbonate Urethane Acrylate Technology (NVP Free)

The following screen ink composition was prepared by first premixing thematerials and then grinding the resultant mixture on a triple roll milluntil a grind of <12 microns (μM) was achieved.

PCUA, RD3/101 ex UCB 40.0 EOEOEA, S256 ex Sartomer 6.0 IBOA, SR506 exSartomer 15.0 ACMO ex Rahn 7.0 UV stabiliser, Genorad ™ 16 ex Rahn 0.3Lucerin ™ TPO ex BASF 4.0 Genocure ™ MBF ex Rahn 2.0 Speedcure ™ ITX exLambson 1.0 Silicone antifoam 0.7 Red 6.0 Filler 18.0 Total (weight %)100.0

Single and multilayer prints of the above screen ink composition wereprinted through a 150-34 mesh onto a polycarbonate substrate and curedusing a medium pressure mercury lamp (80 Wcm⁻¹). The print were examinedfor adhesion, surface hardness, forming, and IMD properties.

B) Experimental Results:

1) Physical Properties

TABLE 1 Pencil Hardness Ink system Hardness* Comments Example 1 H Can bemarked, but good scratch resistance Example 2 HB Moderate scratch,easily marked Example 3 2H Difficult to scratch, excellent adhesionExample 4 H-2H Difficult to scratch, excellent adhesion Example 5 H-2HDifficult to scratch, excellent adhesion Example 6 H Difficult toscratch, excellent adhesion Example 7 H Difficult to scratch, excellentadhesion Example 8 H Difficult to scratch, excellent adhesion *accordingto ASTM D3363, BS 3900-E19, ISO 15184

TABLE 2 Cross-Hatch Adhesion Ink system Ranking** Comments Example 1 4-5No removal Example 2 4 Slight/no removal Example 3 5 No removal Example4 5 No removal Example 5 5 No removal Example 6 5 No removal Example 7 5No removal Example 8 5 No removal **1 = poor (total ink removal). 5 =excellent (no ink removal) according to BS 3900-E6. ISO 24092) Forming Properties

The printed substrates were examined for forming properties using themost commonly used techniques (vacuum thermoform. HPF-Niebling,hydroform, matched metal):

TABLE 3 Vacuum Thermoform Ink system Ranking*** Comments Example 1 4Good forming, suitable for medium to deep draw Example 2 3-4 Mouldmarking can be a problem, inferior at high temps/long cycle timesExample 3 4 Suitable for medium to deep draw, improved resistance tomould marking Example 4 4 Suitable for medium to deep draw, improvedresistance to mould marking Example 5 4 Suitable for medium to deepdraw, improved resistance to mould marking Example 6 4 Suitable formedium to deep draw, improved resistance to mould marking Example 7 4Suitable for medium to deep draw, improved resistance to mould markingExample 8 4 Suitable for medium to deep draw, improved resistance tomould marking

TABLE 4 HPF-Niebling Ink system Ranking*** Comments Example 1 4 Goodforming suitable for medium to deep draw Example 2 4 Good formingsuitable for medium to deep draw Example 3 4 Good forming suitable formedium to deep draw Example 4 4 Good forming suitable for medium to deepdraw Example 5 4 Good forming suitable for medium to deep draw Example 64 Good forming suitable for medium to deep draw Example 7 4 Good formingsuitable for medium to deep draw Example 8 4 Good forming suitable formedium to deep draw

TABLE 5 Hydroform Ink system Ranking*** Comments Example 1 3-4 Moderateforming suitable for medium draw Example 2 4 Good forming suitable formedium to deep draw Example 3 4 Good forming suitable for medium to deepdraw Example 4 4 Good forming suitable for medium to deep draw Example 54 Good forming suitable for medium to deep draw Example 6 4 Good formingsuitable for medium to deep draw Example 7 4 Good forming suitable formedium to deep draw Example 8 4 Good forming suitable for medium to deepdraw

TABLE 6 Matched Metal Ink system Ranking*** Comments Example 1 5Superior resistance to marking from mould tool Example 2 2 Compositiontoo soft. marked by mould tool Example 3 5 Superior resistance tomarking from mould tool Example 4 5 Slightly softer than Example 3Example 5 5 Superior resistance to marking from mould tool Example 6 5Superior resistance to marking from mould tool Example 7 5 Superiorresistance to marking from mould tool Example 8 5 Superior resistance tomarking from mould tool ***1 = poor (not formable), 5 = excellent (deepdraw possible within limits of forming technique)3) Resistance to Wash-Out

The printed substrates were subjected to direct injection with a spruegate, of a polycarbonate backfill. The degree of ink movement (wash-out)was visually assessed and ranked:

TABLE 7 Resistance to PC injection Ink system Ranking**** CommentsExample 1 5 No wash-out, but total solvent removal critical Example 2 2Wash-out, can be improved by use of tie/protective coat e.g. Aqualam ™(ex Coates) Example 3 5 No wash-out Example 4 5 No wash-out Example 5 5No wash-out Example 6 5 No wash-out Example 7 5 No wash-out Example 84-5 Slight wash-out directly around injection point ****1 = poor (inkwash-out), 5 = excellent (no ink wash-out)4) Adhesion or Bond to Injected Backfill Resin

The printed substrates were subjected to injection of polycarbonateresin using a plaque tool with a wide fan gate injection port. The bondstrength between the backfill resin and the printed substrate wasassessed by peel strength analysis:

TABLE 8 Peel Strength Ink system Typical value (N) Range (N) Example 150 50.0-58.0 Example 2 6.7 0.0-8.8 Example 3 51.1 37.8-64.4 Example 452.3 34.2-68.0 Example 5 53 33.8-69.2 Example 6 48.8 30.0-60.25) Resistance to Heat Ageing and Environmental Cycling

Heat ageing and environmental cycling test were undertaken on full IMDparts to ensure that there were no changes to e.g. laminate strength,colouristic properties after the heat/environmental cycles:

TABLE 9 Heat Ageing/Environmental Cycling Delamination Ink system testComments Example 1 Pass Thorough drying critical Example 2 Fail Poorbond strength prior to testing Example 3 Pass No appreciable loss ofproperties Example 4 Pass No appreciable loss of properties Example 5Pass No appreciable loss of properties Example 6 Pass No appreciableloss of properties

TABLE 10 Heat Ageing/Environmental Cycling Ink system Colouristic testComments Example 1 Pass — Example 2 Fail — Example 3 Pass No appreciableloss of properties Example 4 Pass No appreciable loss of propertiesExample 5 Pass No appreciable loss of properties Example 6 Pass Noappreciable loss of properties6) Print Curl

Single and multilayer prints of Example 1 and Example 3 were prepared on125 micron (μm) Bayfol® and assessed for degree of substrate curl ordistortion after 24 hours.

TABLE 11 Ink film Assessment Number of thickness***** of curl Ink systemprint layers (μm) (mm) Comment Example 1 1 5 >45 Very poor 2 12 >47 Verypoor 3 17 >47 Very poor 4 22 49 Very poor Example 3 1 10 2 — 2 16 2-3 —3 22 3 — 4 29 3-6 Very slight curl *****Ink film thickness determinedusing digital micrometer and comparing printed (various number of inkdeposits) and unprinted areas of the substrate.

1. An insert in-mould decoration process, comprising introducing amolding material and an insert decoration into a mold and forming amolded part in which the insert decoration is contained by molding,wherein the insert decoration comprises an energy cured compositionexposed on a surface a substrate, the energy composition comprising aurethane acrylate oligomer having an aromatic or aliphatic polycarbonatebackbone energy-curable resin, additional reactive monomers and/oroligomers and optionally and in an amount not exceeding 10% by weight ofthe composition, a solvent.
 2. The in-mould decoration process accordingto claim 1, wherein the composition is an ink and further comprises apigment or dye.
 3. The in-mould decoration process according to claim 2,wherein the pigment or dye is present in an amount of from 1 to 40% byweight of the composition.
 4. The in-mould decoration process accordingto claim 1, wherein the composition is a photocure composition andfurther comprises a photoinitiator.
 5. The in-mould decoration processaccording to claim 4, wherein the photoinitiator is present in an amountof from 1 to 14% by weight of the composition.
 6. The in-moulddecoration process according to claim 1 wherein the polycarbonatebackbone is aliphatic.
 7. The in-mould decoration process according toclaim 1, wherein the polycarbonate backbone is linear.
 8. The in-moulddecoration process according to claim 1, wherein thepolycarbonate-backboned urethane acrylate oligomer has a molecularweight of from 1,000 to 30,000.
 9. The in-mould decoration processaccording to claim 1, wherein the polycarbonate-backboned urethaneacrylate component is present in an amount of from 5 to 70% by weight ofthe composition.
 10. The in-mould decoration process according to claim1, wherein the polycarbonate-backboned urethane acrylate oligomer is ofthe general formula (I) or (II):

wherein: R₂ and R₃ are such that OCN—R—NCO (where R=R₂ or R₃) representsa diisocyanate; Y represents a hydrogen atom or a methyl group; R₁ andR₄ together with their attached (meth)acrylate group represent theresidue of a hydroxy (meth)acrylate functional unsaturated monomer. 11.The in-mould decoration process according to claim 1, wherein thecomposition comprises additional acrylate monomer and/or oligomer andthe acrylate monomer and/or oligomer is present in an amount of from 0to 80% by weight of the composition.
 12. The in-mould decoration processaccording to claim 11, wherein the acrylate monomer and/or oligomer ismonofunctional.
 13. The in-mould decoration process according to claim1, wherein the composition comprises the reactive monomerN-vinyl-2-pyrrolidone (NVP), in an amount not exceeding 10% by weight ofthe composition.
 14. The in-mould decoration process according to claim1, wherein the composition comprises an organic solvent in an amount notexceeding 5% by weight of the composition.
 15. The in-mould decorationprocess according to claim 1, wherein the composition is free of organicsolvent.
 16. The in-mould decoration process according to claim 2,wherein the ink is printed onto a polycarbonate orpolycarbonate/polyester substrate.
 17. An insert in-mould decorationprocess, comprising introducing a molding material and an insertdecoration into a mold and forming a molded part in which the insertdecoration is contained by molding, wherein the insert decorationcomprises a substrate having an energy cured ink composition exposed ona surface thereof, the energy cured ink composition comprising aurethane acrylate oligomer having an aromatic or aliphatic polycarbonatebackbone energy-curable resin, additional reactive monomers and/oroligomers and optionally and in an amount not exceeding 10% by weight ofthe composition, a solvent, and wherein the exposed ink on the substrateis subjected to polycarbonate or polycarbonate/polyester blend resininjection to provide a polycarbonate or a polycarbonate/polyester blendbackfill adhered to the printed substrate.
 18. The in-mould decorationprocess according to claim 1, wherein the polycarbonate-backbonedurethane acrylate oligomer has a molecular weight of from 3,000 to15,000.